DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements submitted on February 1, 2024 and March 26, 2024 have been considered by the examiner.
Specification
The use of the term “Nafion”, which is a trade name or a mark used in commerce, has been noted in this application. The term should be accompanied by the generic terminology; furthermore the term should be capitalized wherever it appears or, where appropriate, include a proper symbol indicating use in commerce such as ™, SM , or ® following the term.
Although the use of trade names and marks used in commerce (i.e., trademarks, service marks, certification marks, and collective marks) are permissible in patent applications, the proprietary nature of the marks should be respected and every effort made to prevent their use in any manner which might adversely affect their validity as commercial marks.
Claim Objections
Claim 2 is objected to because of the following informalities.
a number should be followed by its unit. The limitation “from about 1 to about 20 minutes” should be edited to read: “from about 1 minute to about 20 minutes”.
line 4 of the claim reads in part: “subjecting the mixture to a ball milling step”. While it is clear that line 4 intends to refer to the mixture described in step (a), applicant is encouraged to modify the limitation to read: “subjecting the mixture from step (a) to a ball milling step” in order to avoid any potential ambiguity.
Claim 6 is objected to because of the following informalities. A number should be followed by its unit.
The limitation “from 3 to 30 wt.%” should be edited to read: “from 3 wt.% to 30 wt.%”.
Claim 15 is objected to because of the following informalities.
a number should be followed by its unit. The limitation “from about 3 to about 15 minutes” should be edited to read: “from about 3 minutes to about 15 minutes”.
Iine 2 of the claim recites the limitation “wherein the ball milling step is performed”. Claim 15 depends on claim 1. Claim 1 defines “ball milling” (line 4). For the purposes of consistency, the limitation of line 2 should be edited to read: “wherein the ball milling is performed”.
Claim 16 is objected to because of the following informalities. A number should be followed by its unit.
The limitation “from about 20 to about 100 microns” should be edited to read: “from about 20 microns to about 100 microns”.
Appropriate correction is required.
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 5 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 5 recites the limitation: “the total mass of water and when present, organic diluent and/or organic solvent” (line 5).
Claim 5 depends on claim 4, which requires an organic solvent.
The phrase “when present” in claim 5 creates a potential contradiction with claim 4 on whether the organic solvent is a required component.
For the purposes of examination, “the total mass” of line 5 will be interpreted to mean the mass of water and organic solvent.
Claim 6 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 6 recites the limitation “the mixture comprising a catalyst, an ionomer and water has a solids content of from 3 to 30 wt%” (line 2).
Claim 6 depends on claim 2. Claim 2 depends on claim 1.
Both claim 1 and claim 2 refer to “a mixture comprising a catalyst, an ionomer and water has a solids content”.
Claim 2 defines a mixture comprising a catalyst, an ionomer and water (line 3). This mixture is subjected to a ball milling step and a filtering step to produce the mixture comprising a catalyst, an ionomer and water referred to in claim 1.
It is not clear which of the two mixtures is referred to by claim 6. It is thus not clear whether the mixture prior to filtering or after filtering is required to have the solids content in the range 3 wt% to 30 wt%.
For the purposes of examination, either interpretation will be considered to meet the claim.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1, 4, 7-10, 17, 19, 21 and 23 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by U.S. Pre-Grant Publication No. 2021/0346879, hereinafter Koshikawa.
Regarding claim 1, Koshikawa teaches a process for the preparation of a catalyst ink formulation.
The process comprises a step of providing a mixture comprising layered double hydroxide (LDH) or platinum (Pt) as catalysts, NAFION as an ionomer and water. The mixture has been subjected to ball milling. The process further comprises a step of subjecting the mixture to an ultrasonication step for 30 minutes (paragraphs [0145-0149, 0004]).
Regarding claim 4, Koshikawa teaches that the mixture comprises ethanol (“organic solvent”) (paragraph [0146]).
Regarding claim 7, Koshikawa teaches that the catalyst is Pt (paragraph [0149]).
Regarding claim 8, Koshikawa teaches that the catalyst is provided on ketjen black (“solid support”) (paragraphs [0146, 0149]).
Regarding claim 9, Koshikawa teaches NAFION (paragraph [0147]) – a perfluorinated polymer.
Regarding claim 10, Koshikawa teaches that NAFION (“ionomer”) is present at 0.3 times the total mass of LDH (“catalyst”) and ketjen black (“solid support”) (paragraph [0147]). This corresponds to a ratio of catalyst including solid support to ionomer of 3.33 to 1.
Regarding claim 17, Koshikawa teaches that the ultrasonication step is performed for a time period of 30 minutes (paragraph [0148]).
Regarding claim 19, Koshikawa teaches that the catalyst ink formulation is spray coated onto carbon paper (“membrane”) (paragraph [0150]).
Regarding claim 21, Koshikawa teaches a process for forming a catalyst coated membrane.
The process comprises a step of providing a catalyst ink formulation comprising LDH or platinum (“catalyst”), NAFION (“ionomer”) and water that has been subjected to ball milling followed by ultrasonication (paragraphs [0145-0149]).
The process further comprises a step of spray coating the catalyst ink formulation onto carbon paper (“membrane”) (paragraph [0150]).
Regarding claim 23, Koshikawa teaches incorporating the catalyst coated carbon paper (“membrane”) into a water electrolyzer (paragraph [0151]). A water electrolyzer may be operated in reverse as a fuel cell.
Claims 21 and 23 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by U.S. Pre-Grant Publication No. 2019/0341639, hereinafter Uchida.
Regarding claim 21, Uchida teaches a process for forming a catalyst-coated membrane. The process comprises a step of providing a catalyst ink formulation comprising platinum (Pt, “catalyst”), polymer electrolyte ionomer and water (paragraph [0062]). The catalyst ink formulation has been subjected to ball milling followed by redispersion in an ultrasonic homogenizer (“ultrasonication”) (paragraph [0062]).
The process further comprises a step of spray coating the catalyst ink formulation onto a membrane (13) (paragraph [0068]).
Regarding claim 23, Uchida teaches a process of incorporating the catalyst coated membrane into a fuel cell (paragraphs [0084, 0092]).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 4, 7-9, 11 and 17-19 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pre-Grant Publication No. 2019/0341639, hereinafter Uchida in view of U.S. Pre-Grant Publication No. 2019/0074533, hereinafter Ghil, with evidence from UH-50 Product Information Sheet, hereinafter SMT.
Regarding claim 1, Uchida teaches a process for the preparation of a catalyst ink formulation.
The process comprises a step of providing a mixture comprising platinum (Pt) as a catalyst, NAFION as an ionomer and water. The mixture has been subjected to ball milling. The process further comprises a step of redispersing the mixture in an ultrasonic homogenizer (“ultrasonication step”) (paragraph [0062]).
The ultrasonication step is performed with the ultrasonic homogenizer UH-50 by SMT Co., Ltd (paragraph [0062]). This ultrasonic homogenizer is a tip-type ultrasonic homogenizer and operates at 20 kHz – see SMT.
Uchida fails to specify the duration of the ultrasonication step.
Ghil teaches dispersing a catalyst ink formulation comprising Pt as catalyst, NAFION as ionomer and water (paragraphs [0034, 0040, 0043, 0050, 0052, 0053]). Ghil teaches that the dispersion may be performed with a sonication treatment at a frequency of 20 kHz using a tip-type homogenizer (paragraph [0054]). Ghil teaches that an appropriate time is 10 minutes to 30 minutes (paragraph [0056]).
Therefore it would have been obvious to the ordinarily skilled artist before the effective filing date of the claimed invention to select a time period of 10 minutes to 30 minutes for the ultrasonication step for the purpose of ensuring that the mixture is sufficiently dispersed.
Regarding claim 4, Uchida teaches that the mixture comprises 2-propanol (“organic solvent”) (paragraph [0062]).
Regarding claim 7, Uchida teaches that the catalyst is Pt (paragraph [0062]).
Regarding claim 8, Uchida teaches that the catalyst is provided on Ta-SnO2 (“solid support”) (paragraph [0062]).
Regarding claim 9, Uchida teaches NAFION (paragraph [0062]) – a perfluorinated polymer.
Regarding claim 11, Uchida teaches that the weight of Pt/Ta-SnO2 (catalyst and solid support) in the mixture is 0.45 g. The weight of water in the mixture is 2 g (paragraph [0062]). The resulting ratio of catalyst and solid support to water is 1:4.44.
Regarding claim 17, Uchida as modified by Ghil teaches that the ultrasonication step is performed for a time period in the range 10 minutes to 30 minutes (Ghil’s paragraph [0056]).
Regarding claim 18, Uchida teaches that the ultrasonication step is performed with the ultrasonic homogenizer UH-50 by SMT Co., Ltd (paragraph [0062]).
This ultrasonic homogenizer operates at 20 kHz – see SMT.
Regarding claim 19, Uchida teaches spray coating the catalyst ink formulation onto a membrane (13) (paragraph [0068]).
Claims 2 and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pre-Grant Publication No. 2019/0341639, hereinafter Uchida in view of U.S. Pre-Grant Publication No. 2019/0074533, hereinafter Ghil as applied to claim 1 above and further in view of U.S. Pre-Grant Publication No. 2009/0239117, hereinafter Yamagata and U.S. Pre-Grant Publication No. 2017/0104222, hereinafter Ikehata.
Regarding claim 2, Uchida teaches providing a mixture comprising Pt as a catalyst, NAFION as an ionomer and water. The mixture is subjected to a ball milling step using zirconia balls in a planetary ball mill for 30 minutes (paragraph [0062]).
Uchida fails to teach: 1) that the time period of the ball milling step is from 1 minute to 20 minutes; and 2) filtering the milled mixture.
Regarding 1), Yamagata teaches a step of ball milling a catalyst ink composition including a catalyst such as Pt, ionomer such as NAFION and a solvent such as water. The ball milling is performed in a planetary ball mill using zirconia balls. Yamagata teaches that the time of the ball milling step may be reduced by increasing the rotational frequency (paragraphs [0056, 0065, 0066, 0068, 0069]). In a specific example, Yamagata teaches a ball milling time of 10 minutes (Table 1).
Therefore it would have been obvious to the ordinarily skilled artist before the effective filing date of the claimed invention to increase the rotational frequency of the ball milling for the purpose of reducing the treatment time and to achieve a treatment time of 10 minutes.
Regarding 2), it is well-known in the art to pass a ball-milled catalyst ink through a mesh filter to remove the balls – see, e.g. Ikehata (paragraph [0065]) .
Therefore it would have been obvious to the ordinarily skilled artist before the effective filing date of the claimed invention to include a filtering step after the ball milling step in Uchida’s method for the purpose of removing the zirconia balls.
Regarding claim 12, Uchida teaches that the ball milling step is performed using zirconia balls (paragraph [0062]).
Regarding claim 13, Uchida teaches that the ball milling step is performed using a planetary ball mill (paragraph [0062]).
Regarding claim 14, Uchida teaches that the ball milling step is performed at a rotation speed of 270 rpm for 30 minutes (paragraph [0062]). Uchida as modified by Yamagata teaches increasing the rotation speed to reduce the treatment time (paragraph [0056]). Yamagata provides an example of a rotation speed of 700 rpm and a milling time of 10 minutes (Table 1).
The ordinarily skilled artist would be capable of selecting an appropriate rotation speed, which balances a desire to reduce the treatment time with the need to sufficiently reduce particle agglomeration in the catalyst ink. Thus it would be within the purview of the ordinarily skilled artist before the effective filing date of the claimed invention to select a rotation speed within the claimed range without undue experimentation and with a reasonable expectation of success.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pre-Grant Publication No. 2019/0341639, hereinafter Uchida in view of U.S. Pre-Grant Publication No. 2019/0074533, hereinafter Ghil, U.S. Pre-Grant Publication No. 2009/0239117, hereinafter Yamagata and U.S. Pre-Grant Publication No. 2017/0104222, hereinafter Ikehata as applied to claim 2 above and further in view of U.S. Patent No. 6,221,523, hereinafter Chun.
Regarding claim 3, Uchida as modified by Ikehata teaches a filtered mixture. Uchida teaches that the mixture includes 1-propanol (paragraph [0062]) – a C3 alcohol.
Uchida as modified by Ikehata fails to teach diluting the filtered mixture.
It is customary in the art to adjust the viscosity of a catalyst ink as desired by adding additional solvent – see, e.g. Chun (col. 4, lines 50-66; col. 5, lines 1-5).
Therefore it would have been obvious to the ordinarily skilled artist before the effective filing date of the claimed invention to adjust the viscosity of the ink as desired following the filtration step by adding additional 1-propanol (C3 alcohol) without undue experimentation and with a reasonable expectation of success.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pre-Grant Publication No. 2019/0341639, hereinafter Uchida in view of U.S. Pre-Grant Publication No. 2019/0074533, hereinafter Ghil as applied to claim 4 above and further in view of Japanese Patent Publication No. 2017/188270, hereinafter Arai. (A machine translation of Arai is included with the present office action).
Regarding claim 5, Uchida teaches that the weight of Pt/Ta-SnO2 (catalyst and solid support) in the mixture is 0.45 g and the amount of Pt supported on the Ta-SnO2 is 17.5 wt% (paragraphs [0061, 0062]). It can thus be computed that the mass of the Ta-SnO2 support in the mixture is 0.37 g.
The weight of water in the mixture is 2 g and the weight of 2-propanol (“organic solvent”) is 1.98 g (paragraph [0062]). Uchida does not specify the weight of the ionomer.
Uchida fails to teach a ratio by mass of ionomer and catalyst including support to water and organic solvent.
Arai teaches a catalyst ink comprising Pt on SnO2 support and NAFION as ionomer (paragraphs [0006, 0017]). Arai teaches that a preferred ratio by mass of the ionomer to the SnO2 support is in the range 0.1 to 0.12 for the purpose of ensuring that the catalyst layer is usable in a wide range of humidity environments and can exhibit sufficient performance from low load to high load (paragraphs [0006, 0007]).
Therefore it would have been obvious to the ordinarily skilled artist before the effective filing date of the claimed invention to select a ratio by mass of the ionomer to the SnO2 support in the range 0.1 to 0.12 for the purpose of ensuring that the catalyst layer is usable in a wide range of humidity environments and can exhibit sufficient performance from low load to high load.
In the combination of Uchida and Arai, the amount by mass of ionomer would be in the range 0.037 to 0.045. The ratio by mass of ionomer and catalyst including support to water and solvent would be about 1:8.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pre-Grant Publication No. 2019/0341639, hereinafter Uchida in view of U.S. Pre-Grant Publication No. 2019/0074533, hereinafter Ghil, U.S. Pre-Grant Publication No. 2009/0239117, hereinafter Yamagata and U.S. Pre-Grant Publication No. 2017/0104222, hereinafter Ikehata as applied to claim 2 above and further in view of Japanese Patent Publication No. 2017/188270, hereinafter Arai. (A machine translation of Arai is included with the present office action).
Regarding claim 6, Uchida teaches that the weight of Pt/Ta-SnO2 (catalyst and solid support) in the mixture is 0.45 g and the amount of Pt supported on the Ta-SnO2 is 17.5 wt% (paragraphs [0061, 0062]). It can thus be computed that the mass of the Ta-SnO2 support in the mixture is 0.37 g.
The weight of water in the mixture is 2 g and the weight of 2-propanol (“organic solvent”) is 1.98 g.
The solids in Uchida’s mixture are the Pt/Ta-SnO2 (catalyst and solid support). The non-solids are water and 2-propanol (“organic solvent”). Uchida teaches that the ionomer is dissolved in 2-propanol (“organic solvent”) – therefore it is considered a non-solid. Uchida does not specify the weight of the ionomer.
Uchida fails to teach a solids content in the mixture.
Arai teaches a catalyst ink comprising Pt on SnO2 support and NAFION as ionomer (paragraphs [0006, 0017]). Arai teaches that a preferred ratio by mass of the ionomer to the SnO2 support is in the range 0.1 to 0.12 for the purpose of ensuring that the catalyst layer is usable in a wide range of humidity environments and can exhibit sufficient performance from low load to high load (paragraphs [0006, 0007]).
Therefore it would have been obvious to the ordinarily skilled artist before the effective filing date of the claimed invention to select a ratio by mass of the ionomer to the SnO2 support in the range 0.1 to 0.12 for the purpose of ensuring that the catalyst layer is usable in a wide range of humidity environments and can exhibit sufficient performance from low load to high load.
In the combination of Uchida and Arai, the amount by mass of ionomer would be in the range 0.037 to 0.045.
The solids content in the combination of Uchida and Arai would then be about 11 wt%.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pre-Grant Publication No. 2019/0341639, hereinafter Uchida in view of U.S. Pre-Grant Publication No. 2019/0074533, hereinafter Ghil as applied to claim 1 above and further in view of U.S. Pre-Grant Publication No. 2009/0239117, hereinafter Yamagata.
Regarding claim 15, Uchida teaches providing a mixture comprising Pt as a catalyst, NAFION as an ionomer and water. The mixture is subjected to a ball milling step using zirconia balls in a planetary ball mill for 30 minutes (paragraph [0062]).
Uchida fails to teach that the time period of the ball milling step is from 3 minute to 15 minutes.
Yamagata teaches a step of ball milling a catalyst ink composition including a catalyst such as Pt, ionomer such as NAFION and a solvent such as water. The ball milling is performed in a planetary ball mill using zirconia balls. Yamagata teaches that the time of the ball milling step may be reduced by increasing the rotational frequency (paragraphs [0056, 0065, 0066. 0068, 0069]). In a specific example, Yamagata teaches a ball milling time of 10 minutes (Table 1).
Therefore it would have been obvious to the ordinarily skilled artist before the effective filing date of the claimed invention to increase the rotational frequency of the ball milling for the purpose of reducing the treatment time and to achieve a treatment time of 10 minutes.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pre-Grant Publication No. 2019/0341639, hereinafter Uchida in view of U.S. Pre-Grant Publication No. 2019/0074533, hereinafter Ghil, U.S. Pre-Grant Publication No. 2009/0239117, hereinafter Yamagata and U.S. Pre-Grant Publication No. 2017/0104222, hereinafter Ikehata as applied to claim 2 above and further in view of U.S. Pre-Grant Publication No. 2008/0166620, hereinafter Fuller.
Regarding claim 16, Uchida as modified by Ikehata teaches filtering the catalyst ink through a mesh filter following the ball-milling step to remove the balls (Ikehata’s paragraph [0065]).
Uchida as modified by Ikehata fails to specify the pore size of the filter.
Fuller teaches a similar ball-milled mixture filtered with a mesh filter having openings with a size of 85 µm (paragraphs [0018, 0023]).
Therefore it would have been obvious to the ordinarily skilled artist before the effective filing date of the claimed invention to use a mesh filter with openings with a size of 85 µm to filter the ball-milled mixture of Uchida for the purpose of removing the balls.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LILIA V NEDIALKOVA whose telephone number is (571)270-1538. The examiner can normally be reached 8.30 - 5.00 PM.
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/LILIA NEDIALKOVA/ Examiner, Art Unit 1724
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